Pressing machine control



G, w. JOHNSON 2,026,508 'PRESSING MACHINE CONTROL Filed April 5, 1935 GEoRGEw. JOHNSON ATTOR Patented Dec.

UNITED STATES PRESSING MACHINE CONTROL George W. Johnson,

Cincinnati, Ohio, assigner to The American Laundry Machinery Company, Norwood, Ohio, a corporation of Ohio Application April 5, 1935, SerialNo. 14,791

11 Claims.

This invention relates to improvements in control mechanism for pressing machines of the type used in laundry and garment work.

It is customary in this type of pressing machine to utilize at least one heated pressing member and it is undesirable that a pressing operation should be carried on after failure of the supply of heating medium to the heated pressing member as the work gradually deteriorates in quality until the operator at a belated moment becomes aware of'the failure of the heating supply. A feature of my present invention is .the arrangement of control mechanism for a pressing machine which prevents the closing and holding closed of a pressing machine upon failure or variation of the supply of heating medium to one of the pressing members.

My invention further contemplates the disabling of the mechanism by which the press is closed and held closed upon failure of the heating medium for one of the pressing members. My improved control mechanism as applied to a pressing machine having fluid actuated maintaining means for holding the head closed involves a structure in which the maintaining means is dependent upon the proper supply of heating medium to one of the pressing members.

Another feature of my invention involves a structure by which the mechanism for holding the press closed depends upon the maintenance of la predetermined pressure in the heating pressure fluid supply for one of the pressing members.

Other features of my invention reside in the structure illustrated in the drawing and described in the specification and the essential features of which Will be summarized in the claims.

In the drawing Figs. 1 and 2 are end elevations partly in section of a pressing machine embodying my invention with the control mechanism somewhat diagrammatically shown. Fig. 1 shows the pressing machine in open position and Fig. 2 shows the same parts when the press is closed.

I have illustrated my invention as applied to a pressing machine of the type illustrated, described and claimed in the copending application of John P. Singiser, Ser. No. 642,053, filed November l0, 1932. This machine has a frame I0 upon which is mounted a stationary pressing bed II. On a bracket of the frame is pivotally mounted a head lever I2 which carries a pressing head I3 into and out of coacting position with the bed. Movement of the head lever is provided by a. toggle I4 extending between the rearward end of the 'head lever and the frame and normally biased in broken position as shown in Fig. 1 by spring I5 which holds the pressing head elevated. For actuating the press a cylinder and provided whose piston I1 is I8 with toggle knuckle I9. I8 is a cam bar 20 having piston motor I6 is connected by 'a rod Carried with the rod a depressed portion 2| for a purpose later described. Motive fluid for actuating motor I6 to close the press is supplied through conduit 22, valve casing 23, conduit 24, valve casing 25, conduit 26, piston valve casing 21 and passageway 5 28. Valve casings 23 and 25 contain normally closed inlet valves 23a and 25o and are actuable by manuals 23o and 25h respectively. Piston valve casing 21 houses a piston 28 having a stem 29a and biased by a spring 29h to the position of Fig. 1 10 wherein passageway 28 communicates with an open exhaust port 33. Upon the supply of pressure fluid through conduit 26, piston 29 moves to the left to the position of Fig. 2 which closes the exhaust port 30 and supplies pressure fluid to moy15 tor I6 which pressure fluid at the same time holds piston 29 in the position of Fig. 2.

Means is provided for maintaining the pressing machine closed under pressure and in the present instance this is a fluid actuated maintaininggg means which more specifically supplies a source of fluid pressure for motor I6 independent of thel valves 23m and 25a. This supply isby way of conduit 3|, valve casing 32 and conduit 33 which communicates with passageway 28. In valve .2 5 casing 32 is a normally closed valve 32ar Vhaving a stem 32b and biased toward closed position by a spring'32c.

My invention is illustrated as applied to this 'control mechanism so that the control mecha- 30 nism is disabled upon failure of the heating tmedium which is supplied to one or both ofthe pressing members. In the present instance the head I3 is heated by a pressure fluid such as steam which is supplied by conduit 34 which has suit- 35 able conduit connections 35 and 33 with the usual hollow chest or head I3. A branch conduit 31 through valve casing 38 and conduit 39 conducts the heated pressing fluid to a small motor 40. The motor 40 has a piston 48a adapted to engage ,40 the stem 32h so that actuation of piston 40a will open valve 32a against the bias of its spring. This opening of valve 32aI is made to depend upon a predetermined closing movement of the press so that the maintaining circuit for holding the ,45 press closed is not energized until the pressing members have reached a safe closed position where the operator may not be injured by placing a hand between the closing pressing members. To this end the valve in casing 38 is controlledV by 59 a predetermined .press closing movement of motor I6. In casing 38 is a normally closed valve 38a having a stem 38h whose free end engages the cam bar 20 previously described. This valve remains closed during the first portion of the v55 stroke of piston I'I until the depressed cam portion 2| arrives beneath the valve stem 38o at which time the valve is opened under the bias of spring 38e which thus supplies motive'fluid to motor 40. 60

It will be evident from the mechanism so far described that in a normal pressing operation, with the parts in the position of Fig. 1, the'operator arranges the lay of the work upon bed Il and depresses manuals 2317 and 25h. Pressure fluid then flows through conduit 26 past valve 29 and through passageway 28 to motor I6 and causes a stroke of piston I1. Toward the end of the power stroke of motor I6 valve 38a is opened by the cam bar 2D and steam is supplied through conduits 31 and 39 to motor 4Q which causes a stroke of piston 40a and opens valve 32a. This establishes the motive iiuid maintaining circuit through conduits 3l and 33 to passageway 28 which holds motor I6 in press closed position. Obviously if the pressure supply of heating uid has failed, or if it is insucient when applied to piston 40a to overcome spring 32e, motor 40 will not be actuated and valve 32a will be maintained upon its seat by its spring 32e. It is also possible by the suitable choice of spring 32e to determine the pressure of supply 34 at which it is desirable to permit press operation, that is to say, the weaker spring 32 is chosen the lower the steam pressure to the pressing head may drop before it becomes impossible to operate the press in its normal manner.

For opening the press treadle 4i is provided pivotally mounted on the frame and biased upwardly by spring 62. A link 43 connects the treadle with b-ell crank 44 which has an arm adapted to engage valve stem 29a upon depression of treadle 4l. This must be actuated long enough to exhaust motive fluid through port 30 until spring I5 has broken the toggles and moved cam portion 2| from beneath valve stem 38h so that the valve stem 38h again rides upon the high portion of the cam bar thus closing valve 38a and cutting oi the motive fluid for motor 43 whereupon valve 32a closes and the press continues to open.

What I claim is:

1. In a pressing machine, a pair of coacting relatively movable pressing members, means for closing the press and holding it closed, a supply of heating iiuid for one of said pressing members, and means for disabling said rst named means by failure of said supply. y

2. In a pressing machine, a pair of coacting relatively movable pressing members, means for closing the press and holding it closed, a supply of heated pressure fluid for heating one of said pressing members, and means for disabling said rst named means upon a predetermined drop in pressure of said supply.

3. In a pressing machine, a pair of coacting relatively movable pressing members, means for closing the press and holding it closed, a supply of heating fluid for one of said pressing members, control mechanism for said means, and means for disabling said control mechanism by failure of said supply.

4. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of heating fluid for one of said members, means for closing the press, and means controlled by said heating supply for holding said press closed.

5. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of heating iluid for one of said members, means for closing the press, and means controlled by said heating supply upon predetermined closure of said press for holding said press closed.

6. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of heated pressure uid for heating one of said members, power means for relatively moving said pressing members together for a pressing opera- 5 tion, a power supply line for said power means,

a normally closed control member in said line, and means actuated by said heated pressure fluid for opening said control member.

7. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of heated pressure fluid for heating one of said members, power means for relatively moving said pressing members together for a pressing operation, a power supply line for said power means, a normally closed control member in said line, and means actuated by a predetermined pressure of said heated pressure uid for opening said control member.

8. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of heated pressure uid for heating one of said members, a iuid motor for relatively moving said pressing members together for a pressing operation, a motive uid supply line for said motor, a normally closed valve in said line, and means actuated by said heated pressure fluid for opening said valve.

9. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of heated pressure fluid for heating one of said members, a fluid motor for closing said press, means for actuating said motor to close the press, motive fluid supply means for said motor Yfor holding said motor in press-closed position,

said supply means including a normally closed valve, and means actuated by said heated pressure fluid for opening said valve.

10. In a pressing machine, a pair of coacting relatively movable pressing members, a supply of 40 heated pressure huid for heating one of said members, a fluid motor for closing said press, means for actuating said motor to close the press, iuid pressure actuated means for maintaining said motor in press-closed position, said maintaining means including a normally closed valve,

a fluid actuated device for opening said valve, conduit means connected with said heated pressure fluid supply and with said fluid actuated device, a normally closed valve in said conduit means, and means for opening said last-named valve upon predetermined press-closing movement of said motor.

11. In a pressing machine, a pair of coacting pressing members, one of which is movable toward and from the other for closing and opening the press, a steam supply for heating one of said members, a fluid motor for moving said movable member from open to closed position and for holding it there, fluid supply means for causing press-closing movement of said motor, maintaining uid supply means for holding said motor in press-closed position, said maintaining supply means including a normally closed valve, a steam actuated device for opening said valve, conduit means connecting said device with said steam supply, a normally closed valve in said conduit means, and means for opening said lastnamed valve by predetermined press-closing movement of said motor.

GEORGE W. JOHNSON. 

